Do your custom stair corners look like this? Very dark when placed under roofs? Want it to look like the outer corner?
The key to making them not turn dark is to change the object type in the OBJD.
- Edit line 0x0009: type
- Change to hex 0x000b or dec 11.
Note: The one issue this causes is the eyedropper tool will not work as expected. It will choose the first modular stair in the catalog instead of the stair corner. For me this is okay, as I have re-categorized these to the stair category.